Effect of environmental changes on diversity and functions of soil microbes in peat lands.

在矿井中，植物残体在低温和高湿度条件下变成泥炭。有机物的分解率非常低，而且营养物质的获得非常缓慢，这取决于矿化率，在矿化率中，纤维素分解细菌起着重要的作用。在这种寡营养生态系统中，影响分解速率的水分水平、矿物供应、基质质量和其他物理和化学因素最近受到自然和人工来源的改变。本研究从日本3个地区不同地理类型的沼泽中分离出纤维素分解细菌，揭示其功能多样性，结果表明：高原沼地Sphagnum mat中主要分离到单细胞形成细菌，而在森林泥炭土和芦苇沼泽中分离到少量单细胞形成细菌，其中纤维素分解细菌以放线菌为主。对分离的单细胞细菌进行了生物系统对c -底物利用模式的研究，并进行了功能分类。从泥炭地分离的分离物利用多种碳氢化合物和少量有机酸和氨基化合物，而从森林泥炭土分离的分离物利用有限的碳氢化合物和某些羧酸和氨基化合物作为c -底物。这些结果可能反映了不同生境中潜在c -底物的差异。

In mires, plant residues become into peat under low temperature and high moisture level condition. Decomposition rate of organic matter is very low and, and nutrients become available very slowly depending on the rate of mineralization, through which cellulose decomposing bacteria play an important roll. In such an oligotrophic ecosystem, moisture level, mineral supply, quality of substrate and other physical and chemical factors, which influence the decomposition rate, are changed recently by natural and artificial sources. In the present study, cellulose decomposing bacteria were isolated from geographically various type of mire in three areas in Japan, to reveal its functional diversity with following results :Mainly single cell forming bacteria was isolated from Sphagnum mat in highland moor, whereas small number of such bacteria was isolated from peat soil in forest and reed marsh, where mainly actinomycetes was dominant as cellulose decomposing bacteria. The isolated single cell bacteria were examined C-substrate utilization patterns by Biolog system and classified functionally different groups. Isolates from sphagnum mat used many kinds of hydrocarbons and small number of organic acids and amino compounds, whereas isolates from peat soil in a forest used limited hydrocarbons and some kinds of carboxylic acids and amino compounds as C-substrate. These results might reflect the difference of potential C-substrates in the habitats where the isolates living wetland soils.